eWall is a powerful SMTP proxy that works with any mail server. It supports major antivirus software and can be easily integrated with popular spam detecting software like SpamAssassin. eWall has a various security options that will protect your mail sever from vandals when they only request a connection, save your precious bandwidth, and control the mail transaction. The flexible system of filters lets you develop the new services for your customers. The filters can be created globally or/and per user/domain. The filters will give you the extraordinary capabilities to modify the message content. For example, you can add custom information to message body, add/remove header fields, modify subject, strip the attachments. With filters you even can control the services and launch external applications. Also, there is a special low-cost X License for XMail and ArGoSoft Mail Servers.